An indexable insert described in Japanese Unexamined Patent Publication No. 2006-88332 (Patent Document 1) has conventionally been known as a cutting insert for use in a milling process of a workpiece that becomes a machined product. The cutting insert described in Patent Document 1 has a major cutting edge including two straight shaped portions, and a minor cutting edge. This contributes to reducing a contact length between the cutting edges and the workpiece so as to reduce cutting resistance.
A highly efficient cutting process has been desired in recent years. Hence, there has been a desire for the cutting process in which a cutting tool body configured to attach the cutting insert thereto has a large axial depth of cut and a large amount of feed. In the cutting insert described in Patent Document 1, the major cutting edge is configured to have the straight shaped portions merely having different cutting edge angles, and the upper surface is a flat surface. Therefore, when the depth of cut is increased, the size of the cutting insert may be excessively increased and chip discharge performance may be insufficient because the major cutting edge has a small cutting edge angle.